1. Field of the Invention
The present invention relates to an OLED and a method of manufacturing the same, and more particularly, to an OLED with a long service life and a method of manufacturing the same.
2. Description of the Related Art
The commercial use of organic light-emitting diodes (OLEDs) in display devices has been increasing. Display devices, such as plain displays, monochrome displays, seven-segment displays, full-color active matrix (AM) displays, and the like, have various types of OLEDs with various properties. As the complexity of display devices increases, requirements of the OLED therein, such as service life duration also increase.
Display devices incorporating OLEDs have been produced since the 1980's. OLEDs can be divided into polymer OLEDs (pLEDs) and small molecule OLEDs (SM-OLEDs). When a display device including OLEDs operates for the first time, the brightness of the OLEDs decays quickly. Such an undesired decay results in a reduced service life. Therefore, in order to stabilize display devices, a burn-in process in which a display device is operated continually for about 24 hours at a predetermined brightness is performed before measurement of the service life. The cause of the initial quick brightness decay in OLEDs is not known.
US 2004/0031917A1 and WO 2003/088371 (UDC) disclose a UV-hardening adhesive developed using UV light. The UV-hardening adhesive is used as an encapsulant. EP 1 351 323 (Kodak) discloses a UV hardening adhesive used to fix a drying agent. WO 2003/083960 (CDT) discloses the use of a photo-resist based on a polyimide material for structuring surfaces of a substrate for inkjet printing. The photo-resist can be structured using UV light. In WO 01/93332 (microemission display), a photo resist that can be structured using UV light is used to separate adjacent pixels and form an active ITO surface. US 2003/0222577 (Ritdisplay Corporation) discloses an OLED display device manufactured using a color down conversion process. In this case, a UV-emitter is used as an OLED material.
No method of preventing an initial quick decrease in the service life of an OLED is has been disclosed. Additionally, in order to perform the burn-in process in which a display device continually operates for a predetermined amount of time (about 24 hours) at a predetermined brightness, each OLED must be continually supplied with power for a long period of time. Therefore, the manufacturing costs for OLEDs increase.